Japanese 4.5×6 folders

Between the 1930s and the 1950s, a good number of Japanese companies, some of them very small, produced a quantity of 4.5×6 folders.

There are many models and variants, but most of them are copies either of the Baldax or of the Ikonta and Nettar. Examples of Baldax copies include the Semi Proud (prewar) and the Semi Olympus (the first camera to wear the Olympus name). Examples of Ikonta copies include the Semi Prince and the Semi Minolta (one of the first cameras to wear the Minolta name), both disputing the . The inspiration sometimes comes from other German cameras as well. The 1937 Auto Semi Minolta has a body copied from the Weltur 4.5×6 and an exposure counter copied from the Plaubel rollfilm backs and Roll-Op II camera. The rangefinder of the Super Semi Proud is also inspired by the Roll-Op II. The Duo Six-20 by Kodak AG was copied by the Semi Prux and Roavic, continued after the war by the Apollo and Mikado.

Most models have a vertical folding bed, while most of the Japanese 6×6 folders have a horizontal folding bed after the Ikonta 6×6. Apart from the Kodak Duo copies mentioned above, the horizontal 4.5×6 folders are generally original Japanese designs, like the Semi Olympus II, the Primo or the Tsubasa Super Semi.

After the war, many models switched from a folding optical finder to a viewfinder enclosed in a top housing, giving a more modern look. The Baldax copies became rare and most models now had a body styled after the Ikonta. Some makers, like Daido or Mihama, made both 4.5×6 and 6×6 models, but the 4.5×6 folders tended to be abandoned first. In general they were considered to be cheaper models, and very few received the advanced features of the last Japanese folders, like the coupled rangefinder or automatic film advance. An exception was the Pearl III by Konishiroku; and its successor the Pearl IV had one of the most advanced designs for any format of folder.

By about 1960, all the Japanese 4.5×6 folders had disappeared. In the 1970s, Fuji unexpectedly launched a 4.5×6 folder again, the rangefinder Fujica GS645. It was the last 4.5×6 folder produced in any country. The later autofocus Fuji GA645 and the rangefinder Bronica RF645 descend in some way from the early 4.5×6 folders, but they no longer have bellows.